Handling Performance - Stock Class Handling

1/4There is a movement underway to enact changes to many current stock class rules that now prohibit the changing of stock components. The need for better-handling cars supercedes the small outlay of cash required to do the job.

It is a basic premise in circle track racing that, in a perfect world devoid of cheaters, the horsepower output of your motor is strictly regulated as opposed to the "run what ya brung" practice, and that most of the performance enhancement should be done with the chassis and through improved driver skills. We know all about illegal high-dollar "stock" engines, and that is another subject altogether. The problem with the chassis rules in many Stock class divisions is that racers are restricted in what they can do to make the car handle better. Let's examine this situation and evaluate how we might be able to influence the governing bodies so that Stock class racing can improve as a whole.

The cars we are talking about are known by various names such as Street Stock, Hobby Stock, Pure Stock, Grand Stock, and Chargers, among other more localized names. The rules among racetracks vary, but most call for the suspension components to remain "OEM stock." That's designed to keep racers from spending money on aftermarket parts. Nonetheless, there's much that can be done to make these cars handle better and be more competitive by allowing changes to the control arm mounting points.

Many restrictions are placed on the circle track racers in the name of cost savings. While most agree that racing needs to be cheaper overall, there are certain areas where a small outlay of cash will reap huge benefits for the race teams, spectators, and track owners. Better competition, combined with fewer wrecks and caution periods, means happier race teams and pleased spectators. Allowing the teams to spend a small amount of money may yield huge benefits.

2/4The car we are most concerned with is similar to this early '80s GM Monte Carlo. This is a dirt Hobby Stock car under construction earlier this year.

Cost is a relative term. Let's examine where the areas of cost related to Stock class circle track racing really lie. The most time and money a racer will spend in the Stock class, not counting the cost of tires, is in paying for and replacing parts such as fenders, spindles, control arms, and so on after the car is wrecked. This is in addition to the time spent searching for proper components. Time is money, isn't it?

It is safe to say that a typical stocker will be involved in many wrecks during the course of a year. If we can reduce the number of crashes, we can reduce the cost to the racer. Allowing the teams to properly set up the car will improve performance, reducing incidents caused by ill-handling race cars.

We receive letters and e-mail requesting advice for improving the handling for Stock class race cars. Among the most popular chassis available now are the GM "metric" cars made from 1979 to 1986 because they are so plentiful. The majority of all Stock class cars are GM cars, many of which are the metric chassis. Although the rear suspension in those cars is not ideal, the front holds the most potential for improvement.

The front geometry design on the Stock class cars is terrible. The moment center is not where it should be, the camber change (severe loss) is far from ideal, and the steering usually has excess Ackermann. The front of the chassis is the most important area on which we can work in order to improve overall handling and chassis-related performance, if the rules would allow us to make those changes.

One step to improve the front geometry is to change the angles of the upper and lower control arms. We can easily do this, if permitted, by installing aftermarket upper control arms, aftermarket adjustable inner mounts, and adjustable mono-ball joints. These parts are not very expensive and could do wonders for the handling of the cars if properly mounted.

Another area where the Stock class racer needs to make adjustments is in weight distribution. If the teams were allowed to install weight jackers, the weight distribution would be easy to adjust. Some racers install spacers above the springs to dial in the crossweight. Why not let them make it a little easier by using screw-weight jackers?

3/4The problems associated with the stock upper control arms are evident in these photos. The upper arms actually have reverse angle to them with the inner mounts higher than the ball joints.

In the grand scheme of things, the Stock class is often a training ground for inexperienced teams to learn how to set up a race car. Why not provide the tools they need to make the necessary setup changes to those cars so that when the time comes to move up in class, the learning curve will be much shorter?

What We Preach In the pages of Circle Track, we preach the importance of proper moment center design, camber change characteristics, and steering that does not produce excess or deficient toe in the turns. We tell racers how to accomplish those ends in a highly detailed way. All of that knowledge makes for a very frustrated Stock class racer when he cannot do anything about the design of his car.

It was far easier when these guys didn't know any better and just went along with the way it was. Unfortunately, that has all changed. Imagine knowing that there is a cure for a certain illness, one that is fairly cheap to buy, and then not being allowed to use it. This is what the Stock class racers are going through right now.

4/4If the racers were allowed to install weight jackers, a lot of time and effort would be saved. The team could dial in the handling balance more easily as track conditions changed.

In many cases, the racers take it upon themselves to bend the rules in their favor. One team made what seemed to be minor changes to the front suspension and it made a world of difference in how the car handled. They simply cut off the upper mounts and lowered them. In the process, they repositioned them so that they had a caster split and the proper cambers on each side of the car. They also installed ball joints with longer shafts to raise the upper ball joints and take angle out of the lower ball joints. The upper arms were cut and rewelded to provide more clearance for the ball joint shaft. This work involved mostly labor, and the only cost was for new ball joints. The old ball joints needed replacement anyhow, so there were really no additional costs, only labor and some welding.

The result of those changes was a better moment center location that made the front end more efficient and allowed the car to turn better. The steering felt better due to the caster split, and the tires had more grip due to the cambers being correct. The driver, a veteran of more than 20 years on dirt, said it was the best-handling car he had ever driven. The whole process took less than four hours.

Promoters, Please Wake Up I believe that the majority of promoters want better competition and more car count for each division that races at their tracks. Therefore, it shouldn't be hard to convince them that allowing these simple changes would benefit everyone involved-racers, fans, and owners. Some- times, the resistance is just a matter of the officials not knowing exactly what the racer is up to when they see a deviation from the rules.

I had such an experience at a touring race when the officials saw that some of the teams, ours included, had changed the shape of the radiator inlet boxes. The reshaping of the top of the box allowed more space for low pressure under the hood, and the car produced more aero downforce as a result. This allowed the car to turn better, which is always helpful. The officials were leaning toward outlawing this modification since none of the current rules covered that part of the car. I had a talk with the top official and explained in detail what was being done and why. I told him that rather than ban the practice, he would do much better by allowing all teams to make the modification, and that the cars would then turn better, resulting in a better show. Once he understood, he agreed to allow the teams to modify the air boxes without restrictions.

Most track officials and owners are in need of this kind of information so that they can make intelligent decisions regarding suspension rules. If everyone in a particular class at your racetrack met with the officials and explained why they needed a change in the rules and how it would benefit all, they would be hard pressed to say no without appearing unreasonable.

What Specifically Needs To Change? The following are areas where the racer should be allowed to make changes. The costs are rela-tively low, and most of the work involves labor, a commodity that is readily available to most racers. Building the car requires a lot of labor involving cutting and welding, so a few more hours is not too much to ask.

* Modify the upper control arm mounts. This can be defined as lowering the existing mounts or allowing aftermarket adjustable upper mounts to be welded onto the chassis.

* Allow the use of aftermarket upper control arms of various lengths so that the racer can modify the cambers and moment center location more easily.

* Allow aftermarket mono-ball joints and/or extended shaft ball joints to help reposition the moment centers and reduce camber change. A step further here would be to allow aftermarket spindles.

* Allow modifications to the upper control arm if it is to remain stock. This is required to eliminate binding when increasing the upper control arm angles.

* Allow the teams to install weight jacking systems in the front and/or rear end of the car so that the crossweight (bite or left-rear weight) can be adjusted for handling balance.

These desired modifications seem so simple when we look at them. By all means, let your officials and especially the track owner and promoter know how you feel. Feel free to show them this article, and e-mail or call the magazine if they have any questions.

We need the entry-level classes, and when these cars are designed right, it can be very good racing both from inside the car as well as when viewed from the grandstands. Then the cars will compete based on superior setups and the driver's skill level. And isn't that the way it's supposed to be?